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  </style></noscript></head><body itemscope itemtype="http://schema.org/WebPage" lang="zh-CN"><div class="container sidebar-position-left page-post-detail"><div class="headband"></div><header id="header" class="header" itemscope itemtype="http://schema.org/WPHeader"><div class="header-inner"><div class="site-brand-wrapper"><div class="site-meta"><div class="custom-logo-site-title"><a href="/" class="brand" rel="start"><span class="logo-line-before"><i></i></span> <span class="site-title">dhd的博客</span><span class="logo-line-after"><i></i></span></a></div><h1 class="site-subtitle" itemprop="description">对酒当歌，人生几何</h1></div><div class="site-nav-toggle"> <button aria-label="切换导航栏"><span class="btn-bar"></span><span class="btn-bar"></span><span class="btn-bar"></span></button></div></div><nav class="site-nav"><ul id="menu" class="menu"><li class="menu-item menu-item-home"><a href="/" rel="section"><i class="menu-item-icon fa fa-fw fa-home"></i><br>首页</a></li><li class="menu-item 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content="/images/avatar.gif"></span><span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization"><meta itemprop="name" content="dhd的博客"></span><header class="post-header"><h2 class="post-title" itemprop="name headline">树莓派折腾日记-数码管显示 ip 地址</h2><div class="post-meta"><span class="post-time"><span class="post-meta-item-icon"><i class="fa fa-calendar-o"></i></span> <span class="post-meta-item-text">发表于</span> <time title="创建时间：2019-07-21 11:32:25" itemprop="dateCreated datePublished" datetime="2019-07-21T11:32:25+08:00">2019-07-21</time> <span class="post-meta-divider">|</span><span class="post-meta-item-icon"><i class="fa fa-calendar-check-o"></i></span> <span class="post-meta-item-text">更新于</span> <time title="修改时间：2019-11-18 15:46:11" itemprop="dateModified" datetime="2019-11-18T15:46:11+08:00">2019-11-18</time></span> <span class="post-category"><span class="post-meta-divider">|</span><span class="post-meta-item-icon"><i class="fa fa-folder-o"></i></span> <span class="post-meta-item-text">分类于</span> <span itemprop="about" itemscope itemtype="http://schema.org/Thing"><a href="/categories/树莓派/" itemprop="url" rel="index"><span itemprop="name">树莓派</span></a></span></span> <span class="post-comments-count"><span class="post-meta-divider">|</span><span class="post-meta-item-icon"><i class="fa fa-comment-o"></i></span> <span class="post-meta-item-text">评论数：</span><a href="/190721-PiLedShowIp.html#comments" itemprop="discussionUrl"><span class="post-comments-count valine-comment-count" data-xid="/190721-PiLedShowIp.html" itemprop="commentCount"></span></a></span> <span id="/190721-PiLedShowIp.html" class="leancloud_visitors" data-flag-title="树莓派折腾日记-数码管显示 ip 地址"><span class="post-meta-divider">|</span><span class="post-meta-item-icon"><i class="fa fa-eye"></i></span> <span class="post-meta-item-text">阅读次数：</span><span class="leancloud-visitors-count"></span></span><div class="post-description">用远程终端控制树莓派，首先要知道树莓派的 ip 地址，本文展示了使用一个四位的七段数码管显示树莓派 ip 地址的实际操作过程。</div></div></header><div class="post-body" itemprop="articleBody"><h3 id="材料清单"><a href="#材料清单" class="headerlink" title="材料清单"></a>材料清单</h3><ul><li>四位七段数码管一个(我用的是共阳极的)</li><li>杜邦线若干(至少要 10 根)</li></ul><h3 id="电路连接"><a href="#电路连接" class="headerlink" title="电路连接"></a>电路连接</h3><h4 id="七段数码管的原理图"><a href="#七段数码管的原理图" class="headerlink" title="七段数码管的原理图"></a>七段数码管的原理图</h4><p><img src="/190721-PiLedShowIp/digit.png" alt="数码管"></p><h4 id="如何驱动"><a href="#如何驱动" class="headerlink" title="如何驱动"></a>如何驱动</h4><ul><li>6 8 9 12 四个引脚用于选择数码管</li><li>11 7 4 2 1 10 5 分别对应数码管的的 A B C D E F G 七个led灯</li><li>通过树莓派的 GPIO 不停地改变这些引脚的状态来使数码管显示数字</li></ul><h4 id="连线图"><a href="#连线图" class="headerlink" title="连线图"></a>连线图</h4><p>树莓派 GPIO 参考图<br><img src="/190721-PiLedShowIp/pi.png" alt="数码管"></p><p>以下表所示的对应关系连线，(ps: 具体可自行分配，仅供参考)</p><table><thead><tr><th style="text-align:right">树莓派 GPIO 功能名</th><th style="text-align:left">对应数码管的引脚</th></tr></thead><tbody><tr><td style="text-align:right">GPIO.0</td><td style="text-align:left">6</td></tr><tr><td style="text-align:right">GPIO.1</td><td style="text-align:left">8</td></tr><tr><td style="text-align:right">GPIO.2</td><td style="text-align:left">9</td></tr><tr><td style="text-align:right">GPIO.21</td><td style="text-align:left">11</td></tr><tr><td style="text-align:right">GPIO.22</td><td style="text-align:left">7</td></tr><tr><td style="text-align:right">GPIO.23</td><td style="text-align:left">4</td></tr><tr><td style="text-align:right">GPIO.24</td><td style="text-align:left">2</td></tr><tr><td style="text-align:right">GPIO.25</td><td style="text-align:left">1</td></tr><tr><td style="text-align:right">GPIO.26</td><td style="text-align:left">10</td></tr><tr><td style="text-align:right">GPIO.27</td><td style="text-align:left">5</td></tr></tbody></table><h3 id="驱动代码"><a href="#驱动代码" class="headerlink" title="驱动代码"></a>驱动代码</h3><p>用 C 语言写的驱动程序，使用了 wiringPi 库</p><p>wiringPi 库用如下方式下载<br></p><figure class="highlight sh"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">git <span class="built_in">clone</span> git://git.drogon.net/wiringPi</span><br></pre></td></tr></table></figure><p></p><p>也可以到 <a href="http://wiringpi.com" target="_blank" rel="noopener">http://wiringpi.com</a> 进行下载</p><p>下面是驱动代码<br></p><figure class="highlight c"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br><span class="line">83</span><br><span class="line">84</span><br><span class="line">85</span><br><span class="line">86</span><br><span class="line">87</span><br><span class="line">88</span><br><span class="line">89</span><br><span class="line">90</span><br><span class="line">91</span><br><span class="line">92</span><br><span class="line">93</span><br><span class="line">94</span><br><span class="line">95</span><br><span class="line">96</span><br><span class="line">97</span><br><span class="line">98</span><br><span class="line">99</span><br><span class="line">100</span><br><span class="line">101</span><br><span class="line">102</span><br><span class="line">103</span><br><span class="line">104</span><br><span class="line">105</span><br><span class="line">106</span><br><span class="line">107</span><br><span class="line">108</span><br><span class="line">109</span><br><span class="line">110</span><br><span class="line">111</span><br><span class="line">112</span><br><span class="line">113</span><br><span class="line">114</span><br><span class="line">115</span><br><span class="line">116</span><br><span class="line">117</span><br><span class="line">118</span><br><span class="line">119</span><br><span class="line">120</span><br><span class="line">121</span><br><span class="line">122</span><br><span class="line">123</span><br><span class="line">124</span><br><span class="line">125</span><br><span class="line">126</span><br><span class="line">127</span><br><span class="line">128</span><br><span class="line">129</span><br><span class="line">130</span><br><span class="line">131</span><br><span class="line">132</span><br><span class="line">133</span><br><span class="line">134</span><br><span class="line">135</span><br><span class="line">136</span><br><span class="line">137</span><br><span class="line">138</span><br><span class="line">139</span><br><span class="line">140</span><br><span class="line">141</span><br><span class="line">142</span><br><span class="line">143</span><br><span class="line">144</span><br><span class="line">145</span><br><span class="line">146</span><br><span class="line">147</span><br><span class="line">148</span><br><span class="line">149</span><br><span class="line">150</span><br><span class="line">151</span><br><span class="line">152</span><br><span class="line">153</span><br><span class="line">154</span><br><span class="line">155</span><br><span class="line">156</span><br><span class="line">157</span><br><span class="line">158</span><br><span class="line">159</span><br><span class="line">160</span><br><span class="line">161</span><br><span class="line">162</span><br><span class="line">163</span><br><span class="line">164</span><br><span class="line">165</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// File Name: led.c</span></span><br><span class="line"></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;stdio.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;signal.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;unistd.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;wiringPi.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;stdlib.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;string.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;sys/socket.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;arpa/inet.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;netinet/in.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;netdb.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;sys/ioctl.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;sys/types.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;net/if.h&gt;</span></span></span><br><span class="line"></span><br><span class="line"><span class="comment">/*</span></span><br><span class="line"><span class="comment"> * </span></span><br><span class="line"><span class="comment"> *    __1__</span></span><br><span class="line"><span class="comment"> *   |     |</span></span><br><span class="line"><span class="comment"> *   6     2</span></span><br><span class="line"><span class="comment"> *   |--7--|</span></span><br><span class="line"><span class="comment"> *   |     |</span></span><br><span class="line"><span class="comment"> *   5     3</span></span><br><span class="line"><span class="comment"> *   |__4__|</span></span><br><span class="line"><span class="comment"> *</span></span><br><span class="line"><span class="comment"></span></span><br><span class="line"><span class="comment"> * 0 -- 0111111 -- 0x3f</span></span><br><span class="line"><span class="comment"> * 1 -- 0000110 -- 0x06</span></span><br><span class="line"><span class="comment"> * 2 -- 1011011 -- 0x5b</span></span><br><span class="line"><span class="comment"> * 3 -- 1001111 -- 0x4f</span></span><br><span class="line"><span class="comment"> * 4 -- 1100110 -- 0x66</span></span><br><span class="line"><span class="comment"> * 5 -- 1101101 -- 0x6d</span></span><br><span class="line"><span class="comment"> * 6 -- 1111101 -- 0x7d</span></span><br><span class="line"><span class="comment"> * 7 -- 0000111 -- 0x07</span></span><br><span class="line"><span class="comment"> * 8 -- 1111111 -- 0x7f</span></span><br><span class="line"><span class="comment"> * 9 -- 1101111 -- 0x6f</span></span><br><span class="line"><span class="comment"> */</span></span><br><span class="line"></span><br><span class="line"><span class="meta">#<span class="meta-keyword">define</span> PIN_NUM 7</span></span><br><span class="line"><span class="meta">#<span class="meta-keyword">define</span> SEL_NUM 3</span></span><br><span class="line"></span><br><span class="line"><span class="meta">#<span class="meta-keyword">define</span> IP_SIZE 16</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">int</span> pins[] = &#123;<span class="number">21</span>, <span class="number">22</span>, <span class="number">23</span>, <span class="number">24</span>, <span class="number">25</span>, <span class="number">26</span>, <span class="number">27</span>&#125;;</span><br><span class="line"><span class="keyword">int</span> sels[] = &#123;<span class="number">0</span>, <span class="number">1</span>, <span class="number">2</span>&#125;;</span><br><span class="line"><span class="keyword">int</span> nums[] = &#123;<span class="number">0x3f</span>, <span class="number">0x06</span>, <span class="number">0x5b</span>, <span class="number">0x4f</span>, <span class="number">0x66</span>, <span class="number">0x6d</span>, <span class="number">0x7d</span>, <span class="number">0x07</span>, <span class="number">0x7f</span>, <span class="number">0x6f</span>&#125;;</span><br><span class="line"></span><br><span class="line"><span class="comment">// 处理 SIGINT 信号，保证程序退出时 GPIO 复位，使得数码管熄灭</span></span><br><span class="line"><span class="function"><span class="keyword">void</span> <span class="title">signal_handle</span><span class="params">(<span class="keyword">int</span> signum)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">    <span class="keyword">int</span> i = <span class="number">0</span>;</span><br><span class="line">    <span class="keyword">for</span>(i = <span class="number">0</span>; i &lt; PIN_NUM; ++i)</span><br><span class="line">        digitalWrite(pins[i], LOW); </span><br><span class="line">    <span class="keyword">for</span>(i = <span class="number">0</span>; i &lt; SEL_NUM; ++i)</span><br><span class="line">        digitalWrite(sels[i], LOW);</span><br><span class="line">    <span class="built_in">exit</span>(EXIT_SUCCESS);</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">void</span> <span class="title">init</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">    wiringPiSetup();</span><br><span class="line">    <span class="keyword">int</span> i = <span class="number">0</span>;</span><br><span class="line">    <span class="keyword">for</span>(i = <span class="number">0</span>; i &lt; PIN_NUM; ++i)</span><br><span class="line">        pinMode(pins[i], OUTPUT);</span><br><span class="line">    <span class="keyword">for</span>(i = <span class="number">0</span>; i &lt; SEL_NUM; ++i)</span><br><span class="line">        pinMode(sels[i], OUTPUT);</span><br><span class="line">    <span class="keyword">for</span>(i = <span class="number">0</span>; i &lt; PIN_NUM; ++i)</span><br><span class="line">        digitalWrite(pins[i], LOW); </span><br><span class="line">    <span class="keyword">for</span>(i = <span class="number">0</span>; i &lt; SEL_NUM; ++i)</span><br><span class="line">        digitalWrite(sels[i], LOW);</span><br><span class="line">    signal(SIGINT, signal_handle);</span><br><span class="line">    <span class="built_in">printf</span>(<span class="string">"Use Ctrl+c to exit.\n"</span>);</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">void</span> <span class="title">flush</span><span class="params">(<span class="keyword">int</span> sel, <span class="keyword">int</span> num)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">    <span class="keyword">int</span> i = <span class="number">0</span>;</span><br><span class="line">    <span class="keyword">int</span> n = nums[num];</span><br><span class="line">    digitalWrite(sels[sel], HIGH);</span><br><span class="line">    <span class="keyword">for</span>(i = <span class="number">0</span>; i &lt; SEL_NUM; ++i)</span><br><span class="line">        <span class="keyword">if</span>(sel != i)</span><br><span class="line">            digitalWrite(sels[i], LOW);</span><br><span class="line"></span><br><span class="line">    <span class="keyword">for</span>(i = <span class="number">0</span>; i &lt; PIN_NUM; ++i)</span><br><span class="line">    &#123;</span><br><span class="line">        <span class="keyword">if</span>(n &amp; (<span class="number">1</span> &lt;&lt; i))</span><br><span class="line">            digitalWrite(pins[i], LOW);</span><br><span class="line">        <span class="keyword">else</span></span><br><span class="line">            digitalWrite(pins[i], HIGH);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">// 获取某个网卡的ip地址</span></span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">getlocalip</span><span class="params">(<span class="keyword">const</span> <span class="keyword">char</span> * eth_inf, <span class="keyword">char</span> *ip)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">    <span class="keyword">int</span> sd;</span><br><span class="line">    <span class="class"><span class="keyword">struct</span> <span class="title">sockaddr_in</span> <span class="title">sin</span>;</span></span><br><span class="line">    <span class="class"><span class="keyword">struct</span> <span class="title">ifreq</span> <span class="title">ifr</span>;</span></span><br><span class="line"></span><br><span class="line">    sd = socket(AF_INET, SOCK_DGRAM, <span class="number">0</span>);</span><br><span class="line">    <span class="keyword">if</span>( <span class="number">-1</span> == sd )</span><br><span class="line">    &#123;</span><br><span class="line">        perror(<span class="string">"Socket error."</span>);</span><br><span class="line">        <span class="keyword">return</span> <span class="number">-1</span>;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="built_in">strncpy</span>(ifr.ifr_name, eth_inf, IFNAMSIZ);</span><br><span class="line">    ifr.ifr_name[IFNAMSIZ - <span class="number">1</span>] = <span class="number">0</span>;</span><br><span class="line"></span><br><span class="line">    <span class="keyword">if</span>( ioctl(sd, SIOCGIFADDR, &amp;ifr) &lt; <span class="number">0</span> )</span><br><span class="line">    &#123;</span><br><span class="line">        perror(<span class="string">"ioctl error."</span>);</span><br><span class="line">        close(sd);</span><br><span class="line">        <span class="keyword">return</span> <span class="number">-1</span>;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="built_in">memcpy</span>(&amp;<span class="built_in">sin</span>, &amp;ifr.ifr_addr, <span class="keyword">sizeof</span>(<span class="built_in">sin</span>));</span><br><span class="line">    <span class="built_in">snprintf</span>(ip, IP_SIZE, <span class="string">"%s"</span>, inet_ntoa(<span class="built_in">sin</span>.sin_addr));</span><br><span class="line"></span><br><span class="line">    close(sd);</span><br><span class="line">    <span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">    init();</span><br><span class="line">    <span class="keyword">int</span> i = <span class="number">0</span> ;</span><br><span class="line"></span><br><span class="line">    <span class="keyword">char</span> ip[<span class="number">16</span>] = &#123;<span class="number">0</span>&#125;;</span><br><span class="line">    <span class="comment">// 此处获取哪个网卡的地址由实际情况而定</span></span><br><span class="line">    <span class="comment">// 我的树莓派是用无线联网的，所以用的 wlan0 </span></span><br><span class="line">    <span class="comment">// 网卡名可通过 ifconfig 命令查看</span></span><br><span class="line">    <span class="keyword">int</span> ret = getlocalip(<span class="string">"wlan0"</span>, ip);</span><br><span class="line">    <span class="built_in">printf</span>(<span class="string">"%s\n"</span>, ip);</span><br><span class="line"></span><br><span class="line">    <span class="comment">// 在局域网下，ip 地址一般只有最后一位不同</span></span><br><span class="line">    <span class="comment">// 只获取点分十进制 ip 地址的最后一位</span></span><br><span class="line">    <span class="keyword">int</span> led0, led1, led2;</span><br><span class="line">    <span class="keyword">if</span>(ret &lt; <span class="number">0</span>)</span><br><span class="line">    &#123;</span><br><span class="line">        led0 = <span class="number">8</span>;</span><br><span class="line">        led1 = <span class="number">8</span>;</span><br><span class="line">        led2 = <span class="number">8</span>;</span><br><span class="line">    &#125;</span><br><span class="line">    <span class="keyword">else</span></span><br><span class="line">    &#123;</span><br><span class="line">        <span class="keyword">int</span> ip_len = <span class="built_in">strlen</span>(ip);</span><br><span class="line">        led0 = ip[ip_len<span class="number">-1</span>] - <span class="string">'0'</span>;</span><br><span class="line">        led1 = ip[ip_len<span class="number">-2</span>] - <span class="string">'0'</span>;</span><br><span class="line">        led2 = ip[ip_len<span class="number">-3</span>] - <span class="string">'0'</span>;</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="keyword">for</span>( ; ; )</span><br><span class="line">    &#123;</span><br><span class="line">        flush(<span class="number">0</span>, led0);</span><br><span class="line">        delay(<span class="number">5</span>);    <span class="comment">// 如果不加延时，显示数字会不清晰</span></span><br><span class="line">        flush(<span class="number">1</span>, led1);</span><br><span class="line">        delay(<span class="number">5</span>);</span><br><span class="line">        flush(<span class="number">2</span>, led2);</span><br><span class="line">        delay(<span class="number">5</span>);</span><br><span class="line">    &#125;</span><br><span class="line"></span><br><span class="line">    <span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure><p></p><h3 id="配置自启动"><a href="#配置自启动" class="headerlink" title="配置自启动"></a>配置自启动</h3><p>在 <code>/etc/init.d/</code> 下新建文件 <code>led_show_ip</code> 并给上执行权限</p><p>文件内容如下<br></p><figure class="highlight sh"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#!/bin/bash</span></span><br><span class="line"><span class="comment"># /etc/init.d/temp-ctrl</span></span><br><span class="line"><span class="comment"># Default-Start: 	2 3 4 5</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">case</span> <span class="string">"<span class="variable">$1</span>"</span> <span class="keyword">in</span></span><br><span class="line">    start)</span><br><span class="line">        <span class="built_in">echo</span> <span class="string">"start temp ctrl"</span></span><br><span class="line">        nohup /home/pi/gpio/led &amp;</span><br><span class="line">        ;;</span><br><span class="line">    stop)</span><br><span class="line">        <span class="built_in">echo</span> <span class="string">"stop temp ctrl"</span></span><br><span class="line">        <span class="built_in">kill</span> -2 $(ps aux | grep -m 1 <span class="string">'/home/pi/gpio/led'</span> | awk <span class="string">'&#123; print $2 &#125;'</span>)</span><br><span class="line">        ;;</span><br><span class="line">    *)</span><br><span class="line">        <span class="built_in">echo</span> <span class="string">"Usage : service led-show-ip start/stop"</span></span><br><span class="line">        <span class="built_in">exit</span> 1</span><br><span class="line">        ;;</span><br><span class="line"><span class="keyword">esac</span></span><br><span class="line"><span class="built_in">exit</span> 0</span><br></pre></td></tr></table></figure><p></p><p>在 <code>/etc/rc.local</code> 中 <code>exit 0</code> 之前添加一行<br></p><figure class="highlight sh"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">/etc/init.d/led_show_ip start</span><br><span class="line"></span><br><span class="line"><span class="built_in">exit</span> 0</span><br></pre></td></tr></table></figure><p></p><h3 id="最终效果"><a href="#最终效果" class="headerlink" title="最终效果"></a>最终效果</h3><p><img src="/190721-PiLedShowIp/result.jpg" alt="数码管"></p></div><footer class="post-footer"><div class="post-tags"> <a href="/tags/树莓派/" rel="tag"># 树莓派</a></div><div class="post-nav"><div class="post-nav-next post-nav-item"><a href="/190713-PiTempCtrl.html" rel="next" title="树莓派折腾日记-自动控制风扇"><i class="fa fa-chevron-left"></i> 树莓派折腾日记-自动控制风扇</a></div><span class="post-nav-divider"></span><div class="post-nav-prev post-nav-item"> <a href="/190726-DesignPatternTemplataMethod.html" rel="prev" title="设计模式－模板方法模式(Template Method)">设计模式－模板方法模式(Template Method)<i class="fa fa-chevron-right"></i></a></div></div></footer></div></article></div></div><div class="comments" id="comments"></div></div><div class="sidebar-toggle"><div class="sidebar-toggle-line-wrap"><span class="sidebar-toggle-line sidebar-toggle-line-first"></span><span class="sidebar-toggle-line sidebar-toggle-line-middle"></span><span class="sidebar-toggle-line sidebar-toggle-line-last"></span></div></div><aside id="sidebar" class="sidebar"><div class="sidebar-inner"><ul class="sidebar-nav motion-element"><li class="sidebar-nav-toc sidebar-nav-active" 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class="site-state-item-name">标签</span></a></div></nav><div class="links-of-author motion-element"><span class="links-of-author-item"><a href="mailto:donghaodong555@foxmail.com" title="E-Mail &rarr; mailto:donghaodong555@foxmail.com" rel="noopener" target="_blank"><i class="fa fa-fw fa-envelope"></i></a></span></div></div></div><div class="post-toc-wrap motion-element sidebar-panel sidebar-panel-active"><div class="post-toc"><div class="post-toc-content"><ol class="nav"><li class="nav-item nav-level-3"><a class="nav-link" href="#材料清单"><span class="nav-number">1.</span> <span class="nav-text">材料清单</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#电路连接"><span class="nav-number">2.</span> <span class="nav-text">电路连接</span></a><ol class="nav-child"><li class="nav-item nav-level-4"><a class="nav-link" href="#七段数码管的原理图"><span class="nav-number">2.1.</span> <span class="nav-text">七段数码管的原理图</span></a></li><li class="nav-item nav-level-4"><a class="nav-link" href="#如何驱动"><span class="nav-number">2.2.</span> <span class="nav-text">如何驱动</span></a></li><li class="nav-item nav-level-4"><a class="nav-link" href="#连线图"><span class="nav-number">2.3.</span> <span class="nav-text">连线图</span></a></li></ol></li><li class="nav-item nav-level-3"><a class="nav-link" href="#驱动代码"><span class="nav-number">3.</span> <span class="nav-text">驱动代码</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#配置自启动"><span class="nav-number">4.</span> <span class="nav-text">配置自启动</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#最终效果"><span class="nav-number">5.</span> <span class="nav-text">最终效果</span></a></li></ol></div></div></div></div></aside></div></main><footer id="footer" class="footer"><div class="footer-inner"><div class="copyright">&copy; <span itemprop="copyrightYear">2019</span><span class="with-love" id="animate"><i class="fa fa-user"></i></span> <span class="author" 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